The primary objective of this research is to investigate the mechanisms which contribute to age-dependent changes in the brain-pituitary-ovarian axis as well as the behavioral consequences of these changes. Studies completed to date demonstrate that regular ovarian function can be reinstated when old, anovulatory female rats are fed a diet supplemented with the catecholamine precursor L-tyrosine. The same diet, when introduced relatively early in the female's life, can significantly prolong regular ovarian function. Further studies are being conducted in an effort to elucidate the mechanisms by which this diet influences ovarian function. Parallel research investigating a variety of behavioral measures demonstrates that age-dependent changes in the frequency and intensity of sexual behavior, the regulation of food intake and locomotor activity occur as a consequence of altered ovarian hormone secretion and not because the female becomes insensitive to the behavioral effects of the hormone.